Creche in bunch of straw Muël

5413
Last modified by the author on 07/04/2017 - 16:46

New Construction

  • Building Type : Preschool, kindergarten, nursery
  • Construction Year : 2014
  • Delivery year : 2014
  • Address 1 - street : 35290 MUëL, France
  • Climate zone : [Dfb] Humid Continental Mild Summer, Wet All Year

  • Net Floor Area : 430 m2
  • Construction/refurbishment cost : 634 198 €
  • Number of Children : 12 Children
  • Cost/m2 : 1474.88 €/m2

Proposed by :

  • Primary energy need
    75.7 kWhep/m2.an
    (Calculation method : RT 2012 )
Energy consumption
Economical buildingBuilding
< 50A
A
51 à 90B
B
91 à 150C
C
151 à 230D
D
231 à 330E
E
331 à 450F
F
> 450G
G
Energy-intensive building

The Community of Municipalities of the Pays de Saint-Méen Montauban has decided to build an early childhood facility to respond to a lack of infrastructures of this nature on the territory. This decision follows a study carried out in 2010 that led the Community of Commons to set up an investment plan for early childhood. The Early Childhood Commission proposed that the building should contain 90% natural materials, possibly local, to reduce the environmental impact and preserve indoor air quality.

Thanks to the conviction of the elected representatives, and in particular the Mayor of Muel who had already carried out projects integrating natural materials, the building was constructed with straw boots, wood and clay. The specifications of the architect thus recommended the use of 90% natural materials.

In order to accommodate 12 children under the best conditions, an approach of consultation made it possible to collect the expectations of all the stakeholders. The inhabitants were also able to take part in a participatory project.

The system retained is a mixed structure wooden frame and post-beam resting on a masonry overhang. It is not braced by panels but with crosses of Saint-André in solid wood to allow the installation of coating on both sides of the wall.

For living areas, the framework is insulated with straw bales, the technical parts and the roof are insulated in cellulose wadding.

Sustainable development approach of the project owner

The system retained is a mixed structure wooden frame and post-beam resting on a masonry overhang. She is not Not braced by panels but with crosses of Saint-André in solid wood (douglas) to allow the installation Of coating on both sides of the wall. For the areas to be lived, the framework is insulated with straw bundles, the technical parts and the roof are insulated in cellulose insulation.

Architectural description

The building was deliberately designed on the ground floor to facilitate access to parents and young children and thus contribute to their well being inside the premises.

Building users opinion

"The community of municipalities has wished to make an exemplary equipment in terms of environmental quality and
Well-being for children. We wanted the project to also serve to raise the awareness of the inhabitants of the territory. "
Marcel Minier, Vice-President of the community of communes, Mayor of Muel.

If you had to do it again?

Technically, the greatest point of vigilance was not the straw but rather the risk of condensation in the roof. The timber company would have preferred wooden panels, without contact with a cold wall. However, the office The ventilation was sufficient and the vapor barrier had a high Sd coefficient.

See more details about this project

 http://www.reseau-breton-batiment-durable.fr/retour_experience/une-creche-en-bottes-de-paille

Stakeholders







Energy consumption

  • 75,70 kWhep/m2.an
  • 93,50 kWhep/m2.an
  • RT 2012

    Heating -> 16 KWHEP / m².year DHW-> 6 KWHEP / m².an Lighting -> 39 KWHEP / m².an Ventilation -> 24 KWHEP / m².an

Envelope performance

    - Floor on solid ground (concrete slab / projected polyurethane / concrete screed), thickness 12cm / 12cm / 6cm, U = 0,206 W / m2.K
    - Exterior wall straw coated lime sand + plaster earth / straw + framing wood / straw /
    Plaster, thickness 5cm / 22cm / 23cm / 4cm, U = 0.173 W / m2.K
    - Walls exterior frame wood steico universal / OSB / cellulose wadding + framework wood / blade
    Ventilated air / plasterboard, thickness 1.8cm / 0.9cm / 2cm / 2cm / 4.4cm / 1.3cm, U = 0.172W / m2.K
    - Roofing of cellulose wadding + wooden framework / OSB, thickness 30cm / 1,8cm, U = 0,145 W / m2.K
    - Combined wood / aluminum windows, Uw = 1.5 W / m2.K Sw = 0.47
    - Combined wood / aluminum window doors, Uw = 1.3 W / m2.K Sw = 0.52
    - Roof windows, Uw = 1,4 W / m2.K
    - Glazed entrance doors, Ud = 1.9 W / m2.K
    - Full external doors, Ud = 1.8 W / m2.K

    I4

  • 0,46

More information

The energy consumption forecast for heating and electricity is 26 000 kWh per year.

Systems

    • Low temperature floor heating
    • Wood boiler
    • Solar Thermal
    • No cooling system
    • Single flow
    • Double flow heat exchanger
    • Solar Thermal

    Thermal solar panels provide a part of the production of hot water. In practice, it turns out that the solar hot water network connecting the panels to the balloon also provides part of the heating of the building. A study is underway to correct this flaw.

Urban environment

  • 2 386,00 m2
  • 18,00 %
  • The Community of Municipalities of Saint-Méen-le-Grand has decided to set up the multi-hospital center in Muel for its central character in the south of the canton and to meet the needs of the families of the surrounding communes. The Local Urban Plan of Muël had planned a plot dedicated to this equipment

Product

    Straw

    Echopaille

    [email protected]

     http://www.echopaille.fr/p/contact-et-rencontres.html

    Second œuvre / Cloisons, isolation

    Part of the insulation of the building is in straw bundles. The straw used (triticale) was grown without herbicides or pesticides in a nearby commune. It was bundled and then stored for drying for 1 year in a well ventilated shed with a roof overhang to prevent it from taking the rain. 450 boots of 30 x 40 x 90 cm were used. Their density, size, weight and moisture content (20% maximum) were verified.

    Thanks to the conviction of the elected representatives, and in particular the Mayor of Muel who had already carried out projects integrating natural materials, the building was constructed with straw boots, wood and clay. The specifications of the architect thus recommended the use of 90% natural materials.

Construction and exploitation costs

  • 14 863
  • 687 409
  • 520 000

Water management

    A rainwater harvesting tank of 5 m3 is provided for watering the garden and washing the room with garbage. It has been designed to allow the supply of sanitary facilities if the regulations permit it in the near future.

Comfort

    The choice of natural materials for the structure helps to ensure good indoor air quality. The contracting authority demanded compliance with the rules of professional straw construction published in 2012 to avoid dealing with specificities inherent in the implementation of "non-standard techniques". Beyond the envelope of the building, the floor coverings are made of latex in the activity rooms and marmoleum in the rooms. Solid wood furniture contributes to the low emission of pollutants in indoor air.

    Le nombre d'heures pendant lesquelles la température est inférieure à 17°C ou supérieure à 27°C en période d'occupation est le plus important pour la salle de vie avec 79h sur l'année, essentiellement en période estivale.

Life Cycle Analysis

    The ecological footprint of the building was a real concern for the project owner who wanted to privilege local or recycled resources: • The timber frame comes from the sawmill of Merdrignac, 25 km from the site, which is sourced from Brittany or western France • Wood siding (Country spruce) is also produced in Brittany, at Saint-Nicolas-du-Tertre (56); • The straw used in insulation comes from a holding located in Saint-Onen-la-Chapelle (35) which practices a reasoned agriculture, it is triticale wheat straw. During drying, it was stored in Mauron (35), a neighboring commune located 7 km from the site • The land intended for plaster was taken directly from the site and then stored by the company to be screened and pigmented before adding lime • Cellulose wadding is produced by the company Cellaouate, located in Morlaix (29), from recycled newspapers • Roofing membrane is produced from recycled tires.

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Author of the page

Rémi Boscher

Directeur


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